(19)

(11)

EP 3 280 867 A1

(12)

(43) Date of publication: 14.02.2018 Bulletin 2018/07 (21) Application number: 16777272.2 (22) Date of filing: 07.04.2016

(51) International Patent Classification (IPC):  E21B 17/02(2006.01) F15D 1/00(2006.01) E21B 41/00(2006.01) (86) International application number: PCT/US2016/026424 (87) International publication number: WO 2016/164570 (13.10.2016 Gazette 2016/41)

(84) Designated Contracting States: AL AT BE BG CH CY CZ DE DK EE ES FI FR GB GR HR HU IE IS IT LI LT LU LV MC MK MT NL NO PL PT RO RS SE SI SK SM TR Designated Extension States: BA ME Designated Validation States: MA MD (30) Priority: 07.04.2015 US 201562144211 P (71) Applicant: Ensco International Incorporated Wilmington, DE 19801 (US)	(72) Inventors: ROPER, Richard Robert Houston, Texas 77057 (US) SHEN, Xiaochun Houston, Texas 77057 (US) LI, Wenzhi Houston, Texas 77057 (US) (74) Representative: Smee, Anthony James Michael  AMS IP Limited 119 Valley Road Rickmansworth, Herts. WD3 4BN Rickmansworth, Herts. WD3 4BN (GB)